1. Field of the Invention
This invention relates to a combination padlock, and particularly to a combination padlock with re-setting mechanism for changing the combination if necessary.
2. Description of the Prior Art
In the prior art, such as U.S. Pat. No. 3,817,063, the combination padlock has a set of combination wheels mounted on a shaft portion on one end of the padlock; the shaft portion has a T-shaped groove to receive a T-shaped locking bar; a spring is mounted between the locking bar and the T-shaped groove. The center of the shaft portion has a round hole for receiving two locking tumblers, between which there is a spring to provide an outward pushing force to the same. A set of combination wheels and a fastening sleeve are mounted on the shaft portion. The combination padlock can be put in locked or unlocked position by means of two locking tumblers, a spring between the tumblers, a T-shaped locking bar, and a set of combination wheels.
The aforesaid prior art is deemed not convenient in operation than a dial type of combination padlock because of only a small part of the combination wheels being exposed to operation, and the wheels having no sufficient width.
In another U.S. Pat. No. 4,615,191, a barrel combination lock, the lock has a steel cable shackle, of which one end has ball grooves 39a to 39d, while the other end thereof has a cable sleeve 21. The cable sleeve 21 and the cap 12 are fixedly attached to one end of the shaft body 13, of which the other end is mounted with a removable end cap 18. The center of the shaft body has an axial hole. One end of the shaft body has several ball holes for receiving several locking balls respectively. Several clutches 14 are mounted around the shaft body; the inner surface of each clutch has several locking ball recesses to be in alignment with the ball holes. The outer surface of each of the clutches is mounted and engaged with a combination wheel by means of projections and recesses thereof. All the combination wheels and clutches are maintained in place with a removable end cap. When the combination lock is in lock-up position, one end of the cable shackle with ball grooves 39a-39d is retained in the axial hole of the shaft body by the locking balls in the ball holes respectively. Before the combination wheels are aligned with the combination numbers set, the locking ball recesses of the clutches are unable to receive the locking balls, i.e., the end with ball grooves is unable to pull out of the lock. When the combination wheels are set at the correct combination numbers, the ball recesses of the clutches are in alignment with the well holes respectively; then, when the ball groove end is pulled out, the locking balls will be moved towards the ball recesses. After the shockle is pulled out, the end cap engaged with the shaft body can be disengaged from each other; the end cap can be moved off along the L-shaped sleeve groove of the shaft body. As soon as the end cap is removed, all the combination wheels can be removed. The combination numbers of the lock may be changed by re-setting the numbers.
The shaft hole of the aforesaid combination lock can only be used for locking up or releasing the shackle end in place by means of the well holes on the shaft body engaged with the locking balls. The structure of the lock is unable to be used in a padlock; further, the coupling structure between the shaft body and the end cap is unable to be used in a padlock.
In another U.S. Pat. No. 5,005,384, the combination padlock is an invention of the present applicant with another person. The prime structure of the padlock comprises a main shaft to be mounted around with a set of combination wheels; the main shaft has a T-shaped slot for receiving a T-shaped block with springs between them. The main shaft has a center hole for mounting two locking tumblers, between which a spring is installed so as to provide the tumblers with a pushing out force. After the main shaft is mounted with the combination wheels and an end cap, the padlock can be used for lock-up or unlocking function by means of the structure among the two locking tumblers, the T-shaped block and T-shaped slot.
In the aforesaid invention, the applicant has discovered that the padlock still has a drawback of inconvenience upon being commercialized, i.e., the change of combination numbers can only be done by using a screwdriver to remove an internal screw first before removing the cap off the lock.